Big Ag subsidies make developing countries’ farm sectors less competitive, undermining fair trade and global food security. This is dangerous in a world that can’t feed itself and faces soaring population growth and intertwined climate, water, food, and energy challenges.

A recent Senate hearing explored allegations that banks had inflated their profits by shuffling commodities among their warehouses to slow delivery and drive up prices. “When bankscontrol both the physical products and the financing,they may be able to put a thumb on the scale to influence supply and demand, and bet accordingly,” U.S. Senator Jeff Merkley said.

With the world’s breadbaskets drying up, agricultural commodity trades are already morphing into virtual water trades. The profits that traders make from price volatility or putting their “thumb on the scale” could result in some very big systemic risks—and billions of hungry and thirsty people. It’s time to get a grip on farm policy.